Installation guide

<rm>

</rm>

</cluster>

Note that when you have finished configuring all of the components of your cluster, you will need to

sync the cluster configuration file to all of the nodes, as described in Section 5.15, “ Propagating the

Configuration File to the Cluster Nodes” .

Note

The order in which the system will use the fencing methods you have configured follows their

order in the cluster configuration file. The first method you configure is the primary fencing

method, and the second method you configure is the backup fencing method. To change the

order, you can remove the primary fencing method from the configuration file, then add that

method back.

5.7.4 . Configuring a Node wit h Redundant Power

If your cluster is configured with redundant power supplies for your nodes, you must be sure to

configure fencing so that your nodes fully shut down when they need to be fenced. If you configure

each power supply as a separate fence method, each power supply will be fenced separately; the

second power supply will allow the system to continue running when the first power supply is fenced

and the system will not be fenced at all. To configure a system with dual power supplies, you must

configure your fence devices so that both power supplies are shut off and the system is taken

completely down. This requires that you configure two instances within a single fencing method, and

that for each instance you configure both fence devices with an actio n attribute of o ff before

configuring each of the devices with an acti o n attribute of o n.

To configure fencing for a node with dual power supplies, follow the steps in this section.

1. Before you can configure fencing for a node with redundant power, you must configure each

of the power switches as a fence device for the cluster. For information on configuring fence

devices, see Section 5.5, “ Configuring Fence Devices” .

To print a list of fence devices currently configured for your cluster, execute the following

command:

ccs -h host --lsfencedev

2. Add a fence method for the node, providing a name for the fence method.

ccs -h host --addmethod method node

For example, to configure a fence method named AP C -d ual for the node no d e-

0 1. example. co m in the configuration file on the cluster node no d e-0 1. exampl e. co m,

execute the following command:

ccs -h node01.example.com --addmethod APC-dual node01.example.com

Red Hat Ent erprise Linux 6 Clust er Administ rat ion